Centrifugal microfluidic platforms are known for various fluidic techniques and operations such as volume definition, valving, and nucleic acid sample preparation. These known techniques were developed for performing chemical and biological assays on compact fluidic disc (CD or Lab-on-Disc) platforms. For instance, a number of examples are described in U.S. Patent Appn. Publ. No. 2009-0221431 and U.S. Pat. Nos. 8,303,911, 8,101,138. However, previously disclosed centrifugal microfluidic platforms were not designed to perform processes having multiple media exchanges, such as those processes utilized in cell growth procedures.
Large scale automated media exchange systems are known that utilize bulky equipment such as external pumps and/or robots for pipetting and aspiration of media into and out of cell containing reservoirs. Several examples are described in U.S. Pat. Nos. 6,673,595, 7,635,575, and 4,696,902. These large scale technologies cannot be easily miniaturized for use in small scale cell culture to fit within small incubators. For most of the smaller scale processes, including in-vitro fertilization carried out in incubators, media exchange is done manually using hand-held pipettes and placing embryos in a dish with a specific media for a specified period of time. At the time of the prescribed change of media, the cells are manually aspirated from the dish and placed into a separate dish with a different type of media. This process involving manual embryo handling is stressful for embryos and can be detrimental to optimal normal cell development. Presently, there are no automated media exchange solutions that can fit inside a bench top incubator.